The growth in the use of electronics on vehicles, for example, earthmoving or construction vehicles, has increased the need for improved and more complex diagnostic and prognostic capabilities.
The effect of this increasing need is that an increasing amount information in terms of quantity, reliability, detail, relating to the operation of the vehicles and its systems is needed.
For example, a vehicle's drivetrain is becoming increasingly more electrical in the nature of electronic controls and diagnostics/prognostics. In order to perform these more complex functions, additional information relating to the operation of the drivetrain is needed.
One type of information that is easily attainable is the rotational speed of the rotating members of the drivetrain. The rotational speed of the output of the engine, torque converter, and transmission can provide an indication of whether the drivetrain is operating correctly, for example, in the desired gear ratio.
However, other transmission and torque converter conditions are not so easily attainable. The torque converter and transmission are operated through a series of clutches which provide various gear ratios. Shifting between gear ratios involves complex timing of the operation of these clutches. In order to provide an indication of whether the clutches are operating correctly, that is, in the right sequence or with the correct timing, it is desirous to acquire more information relating to the timing of the shifting of these clutches.
One way to accomplish this is to use a set of pressure sensors within the torque converter and transmission which would give an indication of the clutch positions. From this sensor information, the timing of the clutches could be determined.
However, torque converters and transmissions are highly engineered devices. The clutches and gears must operate in an extremely coordinated manner. Furthermore, there is not a lot of room within the respective housings. As a result, placing sensors within the transmission and/or torque converter is an expensive undertaking in the terms of engineering and manufacturing costs.
It is therefore desirable to provide an inexpensive and reliable sensor system which provides timing information relating to a shifting operation of a drivetrain.
The present invention is directed at solving one or more of the problems as set forth above.